This invention relates to colored contact lenses and methods of making colored contact lenses.
Colored contact lenses are often used for cosmetic purposes to change the apparent color of a wearer's irises. For example, a person with brown or blue eyes desiring to have green eyes may wear green colored contact lenses to change the apparent color of a wearer's iris to green.
Conventional colored contact lenses (also called cosmetic contact lenses) typically depend on the lens wearer's iris structure to impart an apparent color change to the wearer's iris. Such contact lenses have a colored iris pattern thereon. The pattern comprises discreet opaque color elements with generally non-colored areas (e.g., clear or slightly colored translucent areas) within the interstices of the pattern's color elements. Knapp U.S. Pat. No. 4,582,402 discloses that a contact lens having an adequate amount of discreet opaque pigmented elements in the pattern combined with non-colored areas which permit the wearer's iris structure to show through provides a sufficiently realistic and attractive illusion of iris color change to convince a casual observer that the iris color is natural, at least when the casual observer is at least five feet away.
A disadvantage associated with such prior art cosmetic contact lenses is that the apparent eye color of some people wearing the lenses does not look natural even when the casual observer is more than five feet away. In particular, the apparent color does not look natural when the actual color of the wearer's iris is in sharp contrast with the opaque color of the contact lens pattern. Thus, for many people, such conventional cosmetic contact lenses are not a viable way for changing apparent iris color.
Another disadvantage associated with such prior art cosmetic contact lenses is that even when worn by wearers for whom the contact lenses are intended, the apparent iris color looks natural only when viewed from a distance of at least five feet by an ordinary viewer (i.e., a person having normal 20/20 vision). The ordinary viewer viewing the wearer's eyes from a closer distance might determine that the pattern is not a naturally occurring pattern. In other words, the ordinary viewer might correctly determine that the wearer is wearing colored contact lenses.
Jahnke U.S. Pat. No. 5,414,477 and O'Campo U.S. Pat. No. 5,963,705, like the Knapp patent, disclose contact lenses having opaque intermittent elements and non-colored regions through which significant portions of the wearer's iris structure are visible. These patents disclose making the intermittent elements of a single contact lens having up to three different color elements. The additional lens colors help to blend the color contrasting that occurs between the wearer's iris and the colored elements placed on the contact lens. However, because the typical human iris has more than 1000 distinct colors, the prior art cosmetic contact lenses do not provide anything close to a universally appealing opaque contact lens.
Another disadvantage of conventional cosmetic contact lenses is that such lenses merely attempt to change the apparent color of wearer's irises. The lens patterns of such cosmetic contact lenses do not emulate the detail and attractive structure of a natural human iris.